Talking moving picture system



March 22,

TALKING MOVING PICTURE SYSTEM Filed Oct. 3l, 1928 letectal' EMM@- imply@ [aad Spear/fer "'"CRNEY lsound from a location coinciding wit Patented Mar. 22, 1932 UNITED STATES PATENT OFFICE DAN'FORTH K. GANN ETT, OF JACKSON HEIGHTS, NEW YORK, ASBIGNOR T0 AEERICAN TELEPHONE AND TELEGBAPH (XNMTANY, A CORPORATION 0F NTIL'W YORK TALKING MOVING PICTURE SYSTEM Appliation led October 81, 1928. Serial No. 816,238.

This invention relates to talking moving picture systems, and more particularly to a method of and means for reproducing te t e visual source thereof moving about the picture screen.

One of the present defects of certain talking moving picture systems is that the location of the source of sound in the reproducing process is fixed. This tends to destroy the illusion as the spectator is impressed by the fact that the apparent location of the voice.

does not coincide with the mouth of the moving-ligure thrown on the screen. 'The primary object of the arrangements of the invention is to overcome this defect. `Other objects and features of the invention will appear more fully from the detailed description thereof hereinafter given.

The invention may be more fully understood from the following description, together with the accompanyin drawings, in the Figures 1,2, and 3 of whic theinvention is illustrated. In Fig. 1 is shown a circuit diagram of the recording process of the invention. Fig. 2 is a diagram of the sound reproducing arrangements. Fig. 3 is a diagram showing in more detail a portion of the arrangements of the reproducing mechanism. Similar reference characters have been utilized to denote like parts in all of the fi ures.

n the recording arrangements of Fig. 1, there is shown a camera C. At the extremes of the field or range of the camera are placed our microphones. The microphones M1 and M3 may be placed at the vertical ezttremes-of the field of the camera andthe microphones M2 and M4 at the horizontal extremes.

The output of each microphone is connected to an amplifier, such as the amplifiers A1, A2,'A8. and A4. The output of ampliiier A1 will ybe connected to an amplifier A5 and thence to a recorder R5 for making a record of the sound. The method of recording the sound by device R5 may be any desirable one, such as the phonographic method or the film method. The output of each of the microphones and amplifiers A1, A2, A3,

and-A4 is passed through a detector and then a low pass lter having a cut-off of about l0 cycles. The detectors are shown schematically as D1, D2, D3, and D4. The low pass filters are shown schematicall as F1, F22 F8, and F4. From each detector t ere is obtained a low frequency wave whose instantaneous value depends on the signal strength picked up by the microphone associated therewith. The four low frequency waves are then recorded at the same time and preferably in the same way as the voice, by recorder devices R1, R2, R3, and R4. The sensitivity of each of/the recording arrangements should be the same.

It is pointed out that in the process of recording as thesource of the sound moves about in the field of the picture, the relative strength of the voice waves received by the four microphones varies. As the sound moves from left to right, the sound waves received y by microphone M2 increase in strength. Those received by M4 decrease. Similarly, if the source of sound moves in a vertical direction, the relative strength of the sound wave reaching M1 and M3 varies. Accordingly, the strength of the sound recbythe recorder device R5 and transmitted to the loud speaker 11. The motion of the loud speaker 11 about the two axes is determined in the following manner. The four low frequency waves as recorded by devices R1, R2, R3, and R4 are reproduced and transmitted to the amplifiers A1', A2', Ag', and A4. The low frequency wave from recorder R, will be transmitted to amplifier A1; the wave from 100 ords made by devices R1, R2, R3, and R4l will recorder R2 to A2; that from R8 to AB; that from R4 to A4. The outputs from ampliiers A1 and A3 are connected to aA selfbalancing bridge arrangement in which the galvanometer 1 vrotates if there is a difference of volume from the two ampliiers, and at the same time adjusts a ratio arm 5 to balance the arrangement. When a balance is obtained no current flows through the galvanometer. This adjustmentl takes place very rapidly -so that if the relative strength of the low'I frequency signal from the two records made'from microphones M1 and M3 varies, the galvanometer follows the change with corresponding adjustments.l i In thus moving, the galvanometer 1 also switches a contact arm carrying a ground-connection over a group of, contacts connected to leads designated 9. .A In a similar manner the low frequency records derived from microphones M2 and M4 are caused tozactuate a self-balancing galvanomete'r 2 having a ratio arm 6 and a contact arm 8 with grounded connection, which movesover a group of contacts connected to leads designated 10. t

The leads 9 are designed to control the rotation -of the loud speaker 11 labout the axis a-a,'and the leads 10 are designed to control the rotation of the loud speaker 11 about the,

axis 6'6. This will appear more fully from the diagram shown in member 13. This member 13 rotates about the axis arf-fa. The rotation of member -13V -leads 9, as shown, a circuit 'will be completed f to battery 18, which will energizethe dia onally opposite magnets 14 and 16. This w1 l attract the pole pieces of member 1 3 and ro-- `tate the loud speaker 11 about the axis a`-a.

If the grounded contact member 7 '.'should move to the next succeeding lead, the.\circ'uit would be completed fromA battery 18,` energia'- ing diagonally opposite magnets 15 andl'' and thereby chan e the position of loud speaker 11' about t e axis a-a. The loud speakerv 11 is mounted on the Hat circular member 19 in such a -way that it may be rotated about the axis 6--6 whe'nthe circular member 19 rotates about such axis. This ro-` tation is controlled by a series of diagonally opposite magnets, such asv 21 and 22, mounted on a spherical member 20. The pole pieces of member v19 are shown positioned with respect to magnets 21 and 22. When the groundedv contact arm 8. is in contact, as` shown with one of the leads 10, the circuit is completed from battery 23, energizing the magnets 21 and 22 to control the rotation of the loud speaker 11 about the axis 6-6. Other diagonally opposed magnets, not

ig. 3. In Fig. 3, the loud speaker l1 is shown mounted upon thel if the.

shown, are arranged in similar fashion on thespherical member 2O and energized b'y succeeding ones of the leads 10 to further control the 4rotation of member 19 and loud speaker 11 about the axis 6 6.

As a result of the combined'movements about 'the two axes, the sound is thrown against the screen at a point which moves about in a manner corresponding to the move mentof the object which produced the sound in the original recording process. The sound is then reiiectedfrom the screen to the spectator and appears to originate from the proper location.

While the invention has been disclosed as embodied certain specific arrangements which are deemed desirable, it is understood that-it is capable of embodiment in many other widely varied forms without departing from the spirit of the invention as defined by the. appended claims. What is claimed is:

1. In a talking moving picture system the combination of a producing system comprising a plurality of microphones arranged at various positions with respect to the center of the field of the camera, means for making an audible record from one of said microphones, means for simultaneously making lowv frequency records from all of said microphones, and a reproducing Asystem comprising a loud speaker having directional properties, means for actuating said loud s eaker -from said audible record, and means or controlling the directional properties of said loudspeaker by said low frequency records.

2. In a talking moving picture system the combination of a producing system comprising a plurality of microphones arranged at various positions with respect to the center of the field of the camera, means for making an audible record from onel of said microphones, means for simultaneously making low frequency records from all ofsaid microphones, and a reproducing systemcomprlsmg a moving picture screen capable of reflecting sound, a loud speaker having directional properties pointed at -said screenjfor reproducing said audible record, and means for controlling the directional propertiesof said loud speaker by said' low frequency records.

- '3. In a'talking moving picture system a moving picture screen upon which pictures may be shown and capable of reflecting sound, a plurality of devices for recording the movement of the .visual source of'sound on said screen, a loud speakerhaving a variable direction pointed at said screen for sound reproduction, and r meansl for continuously changing theV direction of said loud speaker 'with respect to the boundaries of said screen in accordance with the record of-said devices. 4. In a talking moving picture system a moving picture screen upon which pictures may be shown and capable of reeoting sound,

a plurality ot low frequency records recording the movementot' the visual source of' sound on said screen, `a loud speaker having directional properties pointed at said screen for sound reproduction, mechanism for revolving said loud speaker about two axes at approximately right angles to each other, and means for controlling said mechanism in accordance with the impressions on said 10W frequency records.

5. ln a talking moving picture system the method of recording sound emitted by a moving source which comprises simultaneously picking up a plurality of portions of the emitted sounds at dierent locations Which are fixed, detecting each of the various portions ot the emitted sounds picked up, selectively transmiting only so much of the various detected sounds as have frequencies lying Within a predetermined subaudible range, and recording the subaudible frequencies selectively transmited.

6. ln a talking moving picture system the lmethod of reproducing speech sounds so that the locations of these sounds will coincide with the visual source thereof moving on the screen which comprises simultaneously picking up a plurality of portions of the emitted sounds at different locations which are fixed, detecting each of the various portions of the emitted sounds picked up, selectively transmitting only so much of the various detected sounds as have frequencies lying within a predetermined suhaudible range, recording upon different records the various subaudible frequencies selectively transmitted, and controlling the directional properties of the speech sounds to be reproduced in accordance with said records. n e

In testimony whereof, I have signed my name to this specification this 29th day of October, 1928.

DANFORTH K. GANNETT. 

